Groundwater modeling is a practice which involves creating a model of a groundwater system. This is usually accomplished on a computer, using specialized software which has been specifically designed for the purpose of groundwater modeling. Groundwater models can also be drawn out on paper or constructed in the form of three dimensional models, although these practices are increasingly rare now that a variety of software products are available.
Being able to model groundwater systems can be tremendously useful for a wide range of applications. Using a model helps people visualize a system which they cannot see, and it can illustrate key points of interest or be used to gather information about a system. People who have difficulty understanding water use policy and other issues sometimes benefit from instruction with a groundwater model in which issues are visually illustrated, rather than just being discussed in the abstract.
Groundwater models map out where supplies of groundwater are located, and how groundwater supplies flow. Hydrologists are involved in the mapping process, along with geologists who study the rock and soil conditions present in a groundwater system. The system can also show sources of groundwater recharge, illustrating where water enters the system.
With a groundwater modeling program, scientists can explore a variety of scenarios. For example, they can place a number of wells in the model to see how much water use the system can sustain, and to explore optimal well placement. They can also introduce pollution to the model, charting how the pollution flows through the groundwater system. This process can also be used in reverse; by plotting the locations from which polluted water samples have been drawn in a groundwater model, scientists can trace their source. This process is used in groundwater remediation to determine who is responsible for pollution and to develop the best angle of attack for dealing with the pollution.
Risk analysis can also involve groundwater modeling, as can more general analysis of groundwater systems. When a developer wants to install a large development, for example, it may be required to submit groundwater modeling data to a planning agency to illustrate how the development will impact groundwater supplies. Groundwater modeling is also used in groundwater monitoring, in which people protect groundwater supplies to ensure that they will stay ample and clean enough for drinking by keeping an eye on groundwater systems and identifying hot spots and problem areas before they get too big to handle.